July 20, 2017
For more than half a century, scientists have dreamed of harnessing an odd quirk of nature— “selfish genes,” which bypass the normal 50/50 laws of inheritance and force their way into offspring—to engineer entire species. A few years ago, the advent of the CRISPR-Cas9 gene editing technology turned this science fictional concept into a dazzling potential reality, called a gene drive. But after all the hype, and fear of the technology’s misuse, scientists are now questioning whether gene drives will work at all.
Gene drive is a molecular technology that forces an edited gene to be passed along into all of an organism’s offspring, overriding nature’s 50/50 inheritance mix. The first human-engineered gene drive was only demonstrated in fruit flies in 2015, but scientists were soon talking about using gene drives to exterminate invasive pests or kill off throngs of malarial mosquitoes.
But soon after, other researchers demonstrated that as an infertility mutation in female mosquitoes was successfully passed on to offspring over many generations, resistance emerged, allowing some mosquitoes to avoid inheriting the mutation. Just as bacteria can develop resistance to antibiotics, wild populations can develop resistance to modifications aimed at destroying them. Gene drive, dead.
Image: By DBCLS 統合TV, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=55175302